1. Field of the Invention
The present invention relates to an interconnecting electrical connector to be provided between a pair of mating connectors or the like for interconnecting them.
2. Description of the Related Art
Such an interconnecting electrical connector is disclosed in U.S. Pat. No. 5,395,252. As FIG. 11 shows, this connector has a contact element 51 which is made by stamping a metal sheet to provide a strip member having a pair of mounting wings 51A and is bent in the direction of sheet thickness to provide the substantially S-shaped contact element. A slit 53 is provided in a housing 52 and has a pair of retention grooves 54 in opposed side walls. The contact element 51 is held in the slit 53 by press-fitting the mounting wings 51A into the retention grooves 54 such that middle portions 51B are brought into spring contact with the side walls of the slit while both of the contact ends 51C project from the slit 51.
When mating connectors 61 and 62, such as circuit boards or IC packages, are mounted on the upper and lower surfaces of the interconnecting connector, the connection pads 61A and 62A are brought into spring contact with the contact ends 51C. In this way, the interconnecting connector is flanked by the mating connectors 61 and 62 to interconnect them.
The contact element of FIG. 11 has two functions; i.e., as a spring to provide contact forces with the mating connectors and a transmission path for transmitting signals. Since it is made in the form of an S-shape to provide a satisfactory spring characteristics, the transmission path becomes long. However, the increased speed of signals has made it difficult to meet the two requirements simultaneously. In transmitting high-speed signals, the shorter the contact element, the lower the self inductance of the transmission line. The short contact elements, however, provide limited movements of the contact points, failing to provide stable spring contacts.
The sliding movement of the contact points 51C with respect to the contact pads 61A and 62A is made by flexure of the contact points 51C about the middle points 51B. However, the contact points 51C extend substantially upwardly from the middle points 51B so that the amount of sliding movement is small. Consequently, the contact points 51C are brought into little sliding contact with the contact pads 61A and 62a, failing to provide the so-called "wiping effects." This leads to poor contact resulting from the accumulation of dirt and dust.